This puzzles me any one got the answer

[metal mania]

This puzzles me any one got the answer.

I'm hugely aspired and impressed by what the members here are doing with respect to making metal detectors and coils. I hope to become proficient and build working metal detectors one day I have been reading basically everything I can including that excellent
Inside the Metal Detector book

slight plug there guys any way back to my question I've watched numerous videos with circuits in of metal detectors home made of course. I hesitate to use that word home made due to the standard the work is perhaps semi-professional what do you guys prefer.

In all the videos the testing is always air testing discrimination etc which is great. I'm curious to why no actual live digs would love to see one perhaps when when I'm able to build a detector I will do one

[mykaitch]

The first test to try on a homebrew is 'in air' if only as a quick check that it might work. I have spent a few hours with an oscilloscope tracing signal paths and measuring pulses etc..but the time comes to go for real. I have learned that the detector must really perform pretty well in air to have a chance of being of any use. I then scatter a few coins on the lawn, test ground bal etc and go over them, then bury a few, and then off for real (if all the tests work out!).